Greenfield township represents an area within the Greenfield township subdivision of the Brown County (South Dakota),
which is not part of any official city, town or other place of the Greenfield township subdivision.
This area is populated by approximatelly 40 people and occupies the area of 37 square miles - 4 square miles represent water areas.
Racial makeup of the population is : White (100%), Two or More races (0%) and (%).
The male part of the population has a median age of 40 and the “median female” is 56 years old.

Statistical data for the Greenfield township based on the 2010 U.S. Census